You can smell or taste your breast milk to see if it's still good.
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If Your Breast Milk Was Left Out, Here's How To Tell If It's Still Good

Like regular milk, tasting it and smelling it can determine if it's OK. (And proper storage.)

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Breastfeeding is touted as the most natural way to feed your baby; still, that doesn’t mean it’s always easy. Not only is the act of nursing itself very complicated, but so are all the guidelines and procedures that go into pumping and storing your milk. Remembering all the details of proper milk care, like time limits and leaving your milk at room temperature, in the fridge, or frozen isn't simple. Like, what if some of your breast milk is left out too long? Do you have to dump breast milk that smells OK? Pouring out liquid gold that could still be good is not something any breastfeeding mother wants to do.

How Long Breast Milk Can Sit Out

But there is a time limit to how long your breast milk should sit out. Dr. Jessica Madden, medical director at Aeroflow Breastpumps, tells Romper that pumped breast milk can be at room temperature for up to eight hours before it goes bad. Still, she adds, “It’s best to use it or store it within four hours.” And if the temperature in your house is very warm, it’s even less time. “Milk needs to be stored sooner than four hours if an environment’s room temperature has been higher than about 85 degrees Fahrenheit.”

And if it’s frozen, that changes things as well. “If thawed from a frozen stash, it needs to be treated like regular food practices — up to two hours at room temperature before needing to be refrigerated," Ashley Georgakopoulos, IBCLC and Motif Medical lactation director, tells Romper.

How To Tell If Your Breast Milk Has Spoiled

But what if your breast milk has been sitting out for about six hours, and it looks fine and smells perfectly fine? How do you know if it’s still good, and if it’s still OK to feed it to your baby? The advice seems to vary. Georgakopoulos recommends not feeding it to your child if it’s been out for longer than four to five hours, saying, “Foreign pathogens and bacterial growth cannot always be detected immediately.” She notes that while you can still use it for topical purposes, like ointments or baths, it shouldn’t be used for feeding.

However, Leigh Anne O’Connor, IBCLC, tells Romper that it depends. “I encourage my families to taste breast milk and get a sense for what your personal milk tastes like. If the milk smells fine and tastes fine, it is likely fine,” she says. If you want to be on the safe side, you can follow Georgakopoulos’ advice, but if you think it’s fine, then go with your gut, mama.

Keep in mind that giving your child contaminated breast milk isn’t a fun experience, to say the least. “The biggest concern with using breast milk that has gone bad is bacterial contamination, which puts your baby at risk of getting sick with an infection,” Madden explains. This can cause diarrhea and vomiting, and she adds, “It’s especially risky to give breast milk that’s gone bad to preemies and/or babies with fragile immune systems.” If you have doubts that your breast milk is still good, then tossing it is the best way to go.

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How To Properly Store Your Breast Milk

To make sure you’re not in a situation when your breast milk goes bad, make sure you’re storing it properly. Georgakopoulos says that freshly expressed breast milk can be kept in the refrigerator for four to five days. “At that point it needs to be used or frozen,” she explains. “If thawed from a frozen stash, it needs to be used within 24 hours and kept in the fridge between use.”

Madden recommends keeping it towards the back of your fridge, rather than the front or on the shelves on the door, so that it stays as cool as possible. You should also date it so you don’t get confused. “It’s important to put the date you pumped your breast milk on every storage bag or bottle,” she says. “Use the oldest milk first, if possible.”

She also says you should store milk in small portions, like no more than 2 to 3 ounces at a time. “This prevents you from thawing out too much milk at once,” she says. Georgakopoulos adds that using milk storage bags is a great way to do this, since it makes it so easy to measure. And if you’re pumping at work and you don’t have access to a fridge for storage, Madden says, “the second best thing to do is to keep it in a cooler bag with ice packs.”

I know, that all seems kind of confusing and complicated. The American Academy of Pediatrics (AAP) offers this conservative and easy to remember guideline to help you keep track of your milk — follow the rule of fours. Four hours at room temperature or four days in the fridge is best for keeping milk safe and fresh.

Keep in mind that your own individual milk can have different spoiling days than the norm. For instance, your milk's taste might begin to change after the fourth day instead of the fifth. Doing regular taste tests can help you figure out when exactly your milk is starting to turn, so you can offer it to your baby or freeze it before it goes bad.

If you are thoroughly confused (as I was) about the best methods for expressing and storing breast milk, getting in touch with your pediatrician or local lactation consultant is always the best option.


Dr. Jessica Madden, medical director at Aeroflow Breastpumps

Ashley Georgakopoulos, IBCLC and Motif Medical lactation director

Leigh Anne O’Connor, IBCLC

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